Memory devices can be provided as internal, semiconductor, integrated circuits in computers or other electronic devices. There are many different types of memory, including random-access memory (RAM), read only memory (ROM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), resistive memory, thyristor RAM (T-RAM), and flash memory, among others.
Fabrication of the different types of memory can include using shallow trench isolation (STI) to electrically isolate conductive semiconductor regions, e.g., lines, pillars, from each other. Fabrication, e.g., patterning and etching processes, then continue to form devices such as transistors, thyristors, and/or capacitors associated with particular memory types and/or components thereof.
Some vertical devices, such as transistors and/or thyristors can be formed having one or more gate structures. However, forming a gate structure adjacent a vertical device can be challenging. For example, it can be difficult to form a vertical gate at a desired height within an STI without causing undesirable effects such as unwanted and/or unintentional removal of hard mask material associated with the fabrication process and/or field oxide, for instance.